Complex numbers: how do I show unique solution?

[LHS]

Homework Statement

[PLAIN]http://img689.imageshack.us/img689/6294/08052011193408.jpg

Homework Equations

The Attempt at a Solution

Hi, I would really appreciate some help on part a, I'm simply getting no where. This is classed as a geometry question, but I haven't covered anything close to this in lectures yet so I'm a little confused, thanks in advance!

 

[Dick]

Take the conjugate of that equation. Then treat the two equations as linear equations in the two variables z and zbar. Eliminate zbar.